---- Reported by brion@pobox.com 2005-05-21 02:14:19 MST ----

Description of Problem:
Writing to a file on a mounted SMB share fails with a lock violation 
exception on Mac OS X.

Steps to reproduce the problem:
1. Mount a writable SMB share from a Windows or Samba server
2. Open a file for writing on the share (File.CreateText, File.OpenWrite 
etc)
3. Write to the file
4. Flush or close the file.

Actual Results:
The file is created ok, but when trying to flush actual written data an 
exception is thrown and the file stays empty:

Unhandled Exception: System.IO.IOException: Lock violation on path 
testfile.txt
in <0x0013c> System.IO.FileStream:FlushBuffer ()
in (wrapper remoting-invoke-with-check) System.IO.FileStream:FlushBuffer ()
in <0x0002c> System.IO.FileStream:Flush ()
in <0x00060> System.IO.StreamWriter:Flush ()
in <0x00050> System.IO.StreamWriter:Dispose (Boolean disposing)
in <0x00034> System.IO.StreamWriter:Close ()
in <0x0005c> LockBug:Main (System.String[] args)


Expected Results:
Should write the file normally.

How often does this happen? 
Every time.

Additional Information:
I've tested shares exported both from Samba on Linux and from Windows XP 
with the same results. What is probably the same bug prevents mcs from 
compiling on a SMB share; the output .exe file is created with 0 byte size 
and the it aborts:

$ mcs LockBug.cs 

** ERROR **: WriteFile returned 33

aborting...
Abort trap


Comparing ktrace/kdump output from opening on a local filesystem and on a 
SMB share, I notice that it's trying to open /proc when writing to the SMB 
share. Mac OS X does not have a /proc filesystem, so this fails.

Mono 1.1.7 and 1.0.5 both seem to fail the same way. I've only tested this 
under Mac OS X 10.4.1 (Tiger), not on older releases.



---- Additional Comments From brion@pobox.com 2005-05-21 02:15:49 MST ----

Created an attachment (id=167993)
Simple test program; run it in a directory on a SMB share.




---- Additional Comments From brion@pobox.com 2005-05-21 02:39:30 MST ----

Created an attachment (id=167994)
Diff of ktrace/kdump output running on local fs and SMB share




---- Additional Comments From brion@pobox.com 2005-05-21 02:41:24 MST ----

The /proc thing only seems to happen when overwriting an existing file 
on the SMB share, and doesn't seem to affect the outcome. The same 
error happens when creating a new file without a previous one, where no 
/proc check occurs.




---- Additional Comments From miguel@ximian.com 2005-05-21 08:33:03 MST ----

In addition to this bug, I would like to get rid of the
lock_file_region block in file_write



---- Additional Comments From dick@ximian.com 2005-05-24 09:12:28 MST ----

Try this patch

Miguel, I'll look at the locking change we discussed when I get back.



---- Additional Comments From dick@ximian.com 2005-05-24 09:13:13 MST ----

Created an attachment (id=167995)
Locking patch




---- Additional Comments From bmaurer@users.sf.net 2005-05-29 19:27:59 MST ----

Miguel checked in this patch.

Imported an attachment (id=167993)
Imported an attachment (id=167994)
Imported an attachment (id=167995)

Unknown bug field "cf_op_sys_details" encountered while moving bug
   <cf_op_sys_details>Mac OS X 10.4.1</cf_op_sys_details>
Unknown operating system unknown. Setting to default OS "Other".